Friday Funny: What’s wrong with this mathematical proof?

Today’s Friday Funny is something to see if you can remember your high school algebra.

The following mathematical proof suggests that 2 = 1, which would definitely cause some issues with the accounting type people out there.

So the question is:

“What’s wrong with this mathematical proof?”

Here is the proof that 2 = 1:

1. Let a and b be equal non-zero quantities
   a = b
2. Multiply both sides by a
   a² = ab
3. Subtract b² from both sides
   a² – b² = ab – b²
4. Factor both sides
   (a – b)(a + b) = b(a – b)
5. Divide out (a – b)
   a + b = b
6. Observing that a = b
   b + b = b
7. Combine like terms on the left
   2b = b
8. Divide by b
   2 = 1      QED

If you can explain what is wrong here, then you might help explain why:

• odd <> even
• black <> white
• night <> day

Post your explanations in the comments.

Enjoy

David

This article was originally posted on https://www.winthropdc.com/blog.